Articles » Lifestyle » General Health » 5 Ways to Measure Body Fat Percentage

5 Ways to Measure Body Fat Percentage

By Marc Perry / September 28, 2018

If you’ve been following BuiltLean, you know losing fat WITHOUT losing muscle is the path to get lean.

So how do you track if you are losing fat, or muscle, or both? Aside from weighing yourself weekly and maintaining strength levels as a good barometer, measuring your body fat percentage can be useful.

I have an overview of the 5 most common methods of how to measure body fat percentage below, along with the ONLY method to perfectly measure body fat percentage.

While these 5 methods vary in accuracy, the key to assessing body fat levels is consistent measurements over time (repeatability) so that you can effectively track your progress.

1. Skin Fold Caliper

The “skin fold” method measures your body fat percentage by pinching your fat with your fingers then measuring the thickness with a body fat caliper. The reading is given in millimeters, which you compare to a chart with age and gender to arrive at your body fat percentage. There are many different types of caliper tests, which range from only one site like with the Accumeasure Body Fat Caliper to a 7 site Jackson Pollack Method (some are as high as 12 sites).



Bottom Line
Skin Fold is hands down the most effective, accurate, practical method to measure and track your body fat percentage. The self-administered Accumeasure Body Fat Caliper retails for under $10 and is sufficient for most people.

2. Bioelectric Impedance Analysis

Bioelectric Impedance Analysis, or BIA, determines the electrical impedance, or opposition to the flow of an electric current through the body. Muscle has high water content, and is highly conductive, while fat has lower water content and is not highly conductive. Based on the strength of the impedance along with height and weight metrics, the BIA scale will estimate fat-free body mass and body fat percentage.

Many consumer weight scales like Tanita Body Fat Monitor Scale also come with BIA capabilities, and there are others that require holding the BIA device in your hands. Because the BIA test is based on body water balance, your state of hydration can impact the level of accuracy.



Bottom line
If you can’t use calipers, this is a far second option. If you have a high body fat percentage (calipers can’t fit around your fat pinch), or you have 35+ pounds to lose, start with BIA, then move to calipers. BIA readings for those with low body fat tend to be completely inaccurate.

3. Anthropometric

This method uses body circumference measurements to estimate body fat percentages. The U.S. Navy method takes waist, neck, and height circumference for men and hips, neck, and height for women.

A U.S. Navy Method calculator is available on this website where you can input your measurements on right hand column. If you don’t have a cloth measuring tape, you can purchase a MyoTape Body Tape Measure, which I’m using to measure my waist in the picture to the right.



Bottom Line
I would consider this method the least accurate because it doesn’t directly measure body fat (or even attempt to). For example, I have around 6% body fat using calipers, but according to anthropometric, my body fat is around 11.5%. If you don’t have a BIA scale, or calipers, it can be a decent start.

4. Hydrostatic Weighing

This method is considered the “Gold Standard” (+/- 1.5% error) of body fat measurement that requires being submerged in a specialized tank of water. Because bone and muscle are more dense than water, a person with a larger percentage of fat free mass will weigh more in the water and have a lower percent body fat. Conversely, a large amount of fat mass will make the body lighter in water and have a higher percent body fat.

Accuracy of the reading is contingent upon blowing all the air out of the lungs during pretest screening. The test takes about 20-30 minutes, costs around $100-150, and is available at research labs, universities, or hospitals.



Bottom Line
If you are extremely curious to get the most accurate measure of your body fat percentage, or you are a bodybuilder, or fitness model tracking your progress, Hydrostatic Weighing may make sense. Otherwise, it’s far too impractical.

5. DEXA Scan

Dual Energy X-ray Absorptiometry known as DEXA is fast becoming the “new” gold standard of body fat measurement because it’s based on a three-compartment model that divides the body into total body mineral, fat-free soft (lean) mass, and fat tissue mass. Hydrostatic Weighing on the other hand only uses a 2 compartment model (fat free mass and fat mass).

DEXA also allows for body fat distribution analysis, so you can figure out with precision how fat is distributed in various parts of your body. In the past, DEXA was only used to measure bone mineral density for ostopenia and osteoporosis in older individuals. The procedure uses a body scanner with low dose x-rays, so it’s completely safe, and takes about 10-20 minutes.



Bottom Line
Similar to Hydrostatic Weighing, if you are extremely curious to get the most accurate reading of your body fat percentage, or you are a bodybuilder, or fitness model tracking your progress, DEXA may make sense. Otherwise, it’s far too impractical and expensive.

All these methods rely on algorithms to convert a measured parameter into an estimate of body fat percentage, so none of them are perfect. Algorithms have variation based on how the underlying assumptions and formulas apply to different populations.

So what’s the only way to measure body fat with perfect accuracy? Well, cutting open a body and examining the fat, like with a cadaver. Seriously, that’s really the only way to measure body fat percentage most accurately.

I plan on digging deeper into each method in future articles, but I hope this was a helpful overview of each method.


  • George says:

    I'm reading of a new device, the bod pod, which measures volume of air. Have you heard of this device?

    • Marc Perry, CSCS, CPT says:

      Hey George, yes I have heard of that device and I should add it to this article. There are a lot of them around - http://www.bodpod.com - in the top right hand corner you can search for facilities in your city/state. My understanding is DEXA is more accurate, but the bod pod is very easy and many athletic teams use the body pod.

  • Maria says:

    I know that BIA devices can be wildly inaccurate, but I am confused about one thing. I am 5'7", 135 pounds, wear a US size 6. I have a Withings scale that says my BF% (not body fat pounds) ranges from 30-32% (42 pounds of fat). The Weight Watchers scale at the beach condo says my BF% is about 22% (30 pounds of fat).

    Why is there such a large discrepancy between the two BIA devices? Should I totally disregard them both? I don't belong to a gym or know any trainers, or I would try the caliper device.

    Thanks so much for your thoughts.

    • Mike S. says:

      Maria - In addition to the things Marc mentioned, I've noticed that foot dampness can cause a huge difference. The instructions for a BIA scale I used to have said feet should be slightly damp but not wet for best results when getting a body fat measurement. I could easily get 10-12% variance in consecutive readings just by varying how damp my feet were.

    • Marc Perry, CSCS, CPT says:

      @Maria - I would suggest trying out the accumeasure skin fold caliper. Given your height/weight and assuming you lift weights a couple times per week and exercise, my guess is you are much closer to 22% than 30%. So assuming a relatively low LBM for your height of 100lb, that would mean you have 25% body fat. I would take the wild guess you had 105lb LBM, which leaves you at 22% body fat. As I state in the article, BIA is very unpredictable. There are a number of reasons why the readings may be different, including the settings you have, such as normal vs. athletic, or the strength of the electric current. I'm going to be adding an AWESOME post that shows 5, or so women and the relative body fat percentages of each, so I'll go down the line and show a woman at 30%, then 25%, then 20%, then 15%, then 12%. It will take some time to add, but should be really good!

  • Maria says:

    Thanks so much for the replies! I read this, and actually ordered the caliper Monday night from Amazon, and received it this afternoon (with the Myotape). I definitely need practice, but I think I fall around 11-12, which puts me in the 23.2-25.3 BF%. I will try to get my husband to use the calipers on me, and see what the reading is. I just measured myself, and went to the Body Tracker Pro site you linked above, and it says 23.3%.

    So pfffft to Withings!

    Mike, I weigh every morning when I wake up, and my feet are pretty dry then. I jumped on the scale yesterday after boot camp, and my feet were definitely sweaty (omg that guy killed us yesterday), and I was 28% (as opposed to typical 30-31%). So your info about foot dampness was on the money for me!

    Thanks again. This has been a great site to read on.

  • Leigh C says:

    Although I am definitely not an expert on this subject I disagree with the caliper method being the favoured choice. I am an athletic 26 year-old woman, and I recently had my body fat % estimated by one of the trainers with a caliper. She had estimated my BF at 13.6%. I have a scale at home (bio-scale) that had been estimating my BF between 20 - 23% during that same period. I recently had my metabolism tested at a facility that does nutrition programs for weight loss and for performance enhancement, and they use a machine that runs a current through the body, while you are laying down. They measured me at 20.1%.
    I'm sure the caliper method is accurate for those who are skilled at using it, but I don't think it would be a good idea for someone to use it if they aren't practiced. If they underestimated my BF by almost 10%, that could be a real hindrance for somebody hovering in the obese range who thinks everything is fine. That would be enough for someone to lose the motivation to lose weight if a woman thinks she is in the healthy range at 24%, when she could really be at 34%!

    • Marc Perry, CSCS, CPT says:

      @Leigh - I appreciate your opinion, but I would have to say that trainer sounds like she had no idea what she was doing! Unless you look extremely lean, a 13.6% BF is just way off and she should have known that. My guess is 9 out of 10 trainers would do a decent job. Before making a final conclusion, I would try out the single site Accumeasure body fat caliper to see what the reading is. For now, I still prefer the caliper, but thanks for sharing your opinion.

  • jimmy baron says:

    THX Marc
    I just volunteered for a long term cancer study that includes among several others metrics measuring % body fat using a BIA. I was 22% just 3% off clinically obese. I don't have six pack but I'm not far off! and I'm well proportioned otherwise. Calipers in the past measured 12% or less. I'm far less active the last 10 years but luckily look similar so I was a little concerned that I might have somehow snuck in a lot of hidden fat. The long term study is going to have some corrupted data IMO.

  • Manoj says:

    Hello Marc, I've recently been reading your blogs and articles very keenly. When it comes to Fat %, I am extremely confused. While my personal trainer measures it by using a caliper and tells me that my Fat % is now 17.5 %, the InBody machine tells my that I have a 26.2% of body fat.

    In this case, having a variance of almost 9%, whom should I trust ? Can you please advise?

    • Marc Perry, CSCS, CPT says:

      @Manoj - If I were you, I would get one more personal trainer to measure my body fat and see what happens. My guess is the caliper is likely more accurate.

  • Manoj says:

    Hi Marc, this was very helpful and it seems my trainer is right. I am between the first 2 builts that you sent. 26% is way too much. Thanks again:-)

  • Hien says:

    Hey Marc,
    Out of all the ways to measure your body fat, what method do you use to measure your body fat?

    • Marc Perry, CSCS, CPT says:

      @hien - skinfold calipers is what I use, I typically use the Jackson Pollock method, although I've found the single site Accumeasure to be pretty good as well. But hands down, skin fold calipers is the way to go if you have under 30% body fat.

  • alen says:

    I am using TANITA scale at home and a hand gadget at the gym. Tanita shows me between 19% at night and 21% morning

    The gadget at the gym which is used only on hands it shows me 15.5% after gym and 18.5% before gym.

    Which is more accurate TANITA scale or the hand gadget

    • Marc Perry, CSCS, CPT says:

      @Alen - The tanita probably, but neither is very accurate. Check out this post I just added which may be helpful for you - Body Fat Percentage Pictures Of Men & Women.

  • Stefanie says:

    Thank you. Have written an updated article on this topic?

    • Marc Perry, CSCS, CPT says:

      Hey Stefanie, I have not. But if you have any questions, feel free to ask